Datasheet

50
55
60
65
70
75
80
85
90
95
100
0
1 2
3
4
5 6
LoadCurrent- A
Efficiency-%
VIN=12V
Fsw=500kHz
VOUT =5V
VOUT =3.3V
VOUT =1.8V
VOUT =1.2V
VOUT =0.8V
T =roomtemperature,
noairflow
A
25
50
75
100
125
150
0 0.5 1 1.5 2 2.5 3 3.5 4
Pic-ICPowerDissipation-W
T -JunctionTemperature-°C
J
TPS54620
SLVS949C – MAY 2009– REVISED MAY 2011 www.ti.com
JUNCTION TEMPERATURE EFFICIENCY
vs vs
IC POWER DISSIPATION LOAD CURRENT
Figure 51. Figure 52.
Thermal Performance
Figure 53. Thermal Signature of TPS54620EVM-374 Operating at
VIN=12V,VOUT=3.3V/6A, T
A
= Room Temperature
Fast Transient Considerations
In applications where fast transient responses are very important, the application circuit in Figure 34 can be
modified as shown in Figure 54 which is a customized reference design (PMP4854-2, REV.B).
The frequency responses of Figure 54 is shown in Figure 55. The crossover frequency is pushed much higher to
118kHz and the phase margin is about 57 degrees.
For more information about Type II and Type III frequency compensation circuits, see Designing Type III
Compensation for Current Mode Step-Down Converters (SLVA352) and Design Calculator (SLVC219).
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